The invention relates to gas-blast switches of the type having a housing filled with insulating gas and two switch pieces movable relative to each other along an axis.
One type of switch in the prior art described, for example, in the German Patent Specification No. 2,811,508. In known switches, quenching gas heated up by the switch arc is led into a pressure chamber in which it blows the switch arc into the expansion chamber while under high pressure after the release of a discharge opening. So that such a switch works satisfactorily within a wide amperage range, it is necessary that a device be provided which essentially consists of a tube-shaped extension and interacts with the movable switch piece and allows the quenching gas located in the pressure chamber to escape in delayed manner into the expansion chamber and also that the outer part of the pressure chamber be protected against excessive pressures by a valve.